Download Native frog (Leiopelma spp.) recovery plan

Native Frog ( Leiopelma spp.)
Recovery Plan
Threatened Species Recovery Plan No. 18
Department of Conservation
Threatened Species Unit
PO Box 10-420
Wellington
New Zealand
Prepared by:
Donald G. Newman
Science & Research Division
Department of Conservation
for the Threatened Species Unit
© March 1996, Department of Conservation
ISSN 1170-3806
ISBN 0-478-01805-3
Cover photo: I. G. Crook, Department of Conservation
CONTENTS
page
1.0
Introduction
1
2.0
Past Distribution
3
2.1
2.2
2.3
2.4
2.5
3
3
3
4
4
3.0
4.0
Leiopelma hamiltoni
Leiopelma hochstetteri
Leiopelma waitomoensis (extinct)
Leiopelma markhami (extinct)
Leiopelma auroraensis (extinct)
Present Distribution
5
3.1
3.2
3.3
3.4
3.5
5
5
5
5
6
Hamilton's frog
Maud Island frog
Archey's frog
Hochstetter's frog
Captive stocks
Threats to Native Frogs
7
4.1
4.2
4.3
4.4
4.5
7
7
7
8
8
Hamilton's frog
Maud Island frog
Archey's frog
Hochstetter's frog
Global declines of amphibian populations
5.0
Ability to Recover
6.0
Options for Recovery
11
6.1
6.2
6.3
6.4
11
11
12
13
Hamilton's frog
Maud Island frog
Archey's frog
Hochstetter's frog
9
7.0
Recovery Strategy: Goal and Objectives
15
8.0
Recovery Strategy: Work Plan
17
9.0
Research Priorities
25
References
27
Acknowledgements
29
Appendix 1: Estimate of Funding Required
Appendix 2: Monitoring Techniques for Native Frogs
Appendix 3:Advocacy Pamphlet
Appendix 4: Published Recovery Plans
Figure 1: Former distribution of Leiopelma taxa identified from
subfossils (Bell 1994, after Worthy 1986, 1987b)
4
Figure 2: Known distribution of extant Leiopelma species (Bell 1994)
6
1.0 Introduction
The native frogs of New Zealand, Leiopelma spp., are regarded as amongst the most
primitive living in the world today. Primitive features, some of which are shared
with South American fossil frogs of Jurassic age (195 to 136 million years ago), are
the presence of nine presacral vertebrae (most living frogs have eight or fewer),
amphicoelous vertebrae, free ribs (not fused to the vertebrae) and the retention in
the adult of a "tail-wagging" muscle. These features are present in the North
American tailed frog, Ascaphus truei, which of living species is considered to be
most closely related to Leiopelma. Recent studies, however, support separation of
the two genera into separate families (Ascaphidae and Leiopelmatidae (e.g., Green &
Cannatella 1993) - both genera included in the suborder of "archaic frogs", the
Archaeobatrachia (Duellman 1975).
New Zealand's native frog fauna consists of three living described species:
Hochstetter's frog, Leiopelma hochstetteri, which occurs in forested patches of the
North Island from Northland to Pureora and East Cape, and on Great Barrier Island;
Archey's frog, Leiopelma archeyi, found on the Coromandel Range; and Hamilton's
frog, Leiopelma hamiltoni, restricted to Maud and Stephens Islands in the Cook
Strait-Marlborough Sounds region. Electrophoretic evidence recently acquired,
indicates that the Stephens Island and Maud Island populations of L. hamiltoni are
distinct species (B.D. Bell, C.H. Daugherty & J.M. Hay, pers. comm.). Consequently,
only the Stephens Island form corresponds to L. hamiltoni (sensu stricto) while the
Maud Island form is as yet unnamed. This recovery plan covers each form separately.
The status of the Stephens Island species (L. hamiltoni) is of particular concern as it
is confined to a 600m2 boulder tumble near the island's summ it and the population
consists of only a few hundred individuals (Newman 1990, Brown 1994). In 1991
native frogs resembling L. archeyi were discovered with L. hochstetteri in
Whareorino Forest, western King Country; the taxonomic status of these `Archeytype' frogs awaits confirmation, but allozyme electrophoresis indicates that this
population is indeed L. archeyi (B.D. Bell & R.A. Hitchmough, pers. comm.).
A clear separation exists between L. hochstetteri and the other living native frogs.
Differences occur in their ecology and habitat requirements, water metabolism,
morphology and development, karyotype (chromosome number and type) and liver
and serum proteins (e.g. Bell 1982, Bell et al. 1985, Cree 1985, 1988, Daugherty et al.
1981, 1982). Archey's, Hamilton's and Maud Island frogs can be considered
terrestrial while Hochstetter's frogs are semiaquatic, inhabiting stream verges and
seepage areas. The extent of the separation has prompted suggestions (e.g., Green et
al. 1989; Bell 1994) that generic differentiation of the two groups seems warranted.
Individual Hochstetter's frogs may have widely different chromosome numbers,
resulting from additional, or supernumerary, chromosomes (e.g., Green 1988, 1994).
Different populations may be cytogenetically distinctive with specimens from Mt.
Moehau, Coromandel, having among the highest numbers of supernumerary
chromosomes found in any type of animal. Further, North Island Hochstetter's frogs
uniquely possess a univalent, female-specific chromosome; other animals, including
L. hochstetteri from Great Barrier Island have sex chromosomes in pairs
1
(Green et al. 1993). Such findings suggest that at least some conservation measures
for L. hochstetteri might be best framed population by population rather than at the
species level (Green 1994), even though much cytogenetic variation may occur
within populations (B. Waldman, pers. comm.).
Subfossil remains indicate that native frogs were once widely distributed throughout
New Zealand and that formerly, several more species existed (Worthy 1987a, b). The
distributions of all living species have been reduced during human occupation of
the country and although the frogs have benefited from legal protection since 1922,
their mainland habitats are still being lost (Bell 1985). According to the
Department's species ranking system (Molloy & Davis 1994), Hamilton's frog is in
category `A' (`requiring urgent recovery work'), and Maud Island, Archey's and
Hochstetter's frogs are in category `B' (`requiring work in the short term'). Using the
most recent IUCN (International Union for the Conservation of Nature) Red Data
Book categories, Bell (1994) has suggested that the appropriate classification for
each would probably be L. hamiltoni (= endangered), L. Maud Island (= vulnerable),
L. archeyi (= at risk), and L. hochstetteri (= at risk, but of less concern than L.
archeyi).
This recovery plan has been produced as a response to halt, as far as is practicable,
any further declines in four species of considerable evolutionary importance: four
frogs which make a special contribution to New Zealand's biodiversity. The plan
establishes a long-term (50-year) goal of maintaining and enhancing existing genetic
stocks of native frogs, and a series of aims over the next five years to work towards
that goal. The key aims include maintaining all known populations as far as possible,
establishing new populations of Hamilton's and Maud Island frogs, setting up longterm monitoring sites for all species of native frogs, identifying areas of potential
habitat worth searching to try and locate further, as yet unknown, frog populations,
and improving captive husbandry techniques - especially those involved in raising
j uveniles through to adulthood.
Where frogs co-exist with other threatened species, especially those highly sensitive
to habitat degradation, conservation measures will be linked. Management of
Hochstetter's and Archey's frogs, in particular, will rely on effective advocacy and
habitat management and will therefore have strong links with land management
strategies (e.g., DoC Conservation Management Strategies, local government plans).
The plan will serve to guide the Department in its management of native frogs.
Implementation of the recovery strategy will be overseen by the Frog Recovery
Group and will be dependent on and vary with the resources and information
available at any time. The Frog Recovery Group members are representatives of.
Northland, Auckland, Waikato, Bay of Plenty, East Coast and Nelson/Marlborough
Conservancies, Threatened Species Unit and Science & Research Division of the
Department of Conservation; Victoria University of Wellington.
NOTES TO SECTION 1
vertebral centra are slightly biconcave or flat terminally and separated by
intervertebral cartilage.
2
2.0 Past Distribution
Subfossil distributions of Hochstetter's and Hamilton's frogs show that until the late
Holocene (within the last 2000 years) these species ranged from Punakaiki, on the
west coast of the South Island, to Waitomo in the North Island; L. hamiltoni was still
present in the Waitomo area till at least 1680 years ago (Worthy 1987b, but see
section 2.1, pg 3). As yet, no subfossil material positively referrable to Archey's frog
has been recovered, the skeleton of this species being identical to that of L.
hamiltoni in all aspects except size (Worthy 1987a). Also, it has yet to be
determined if Hamilton's and Maud Island frogs can be distinguished from their
skeletons alone.
Three further native frogs have been described solely from subfossil material:
Leiopelma waitomoensis, an offshoot of the L. archeyi/L. hamiltoni lineage, and
Leiopelma markhami and Leiopelma auroraensis, which are more closely related
to L. hochstetteri (Worthy 1987a). Worthy (1987b) has mapped the distribution of
native frog subfossil sites; nearly all the remains examined have been found in cave
deposits in the karst regions of New Zealand.
2.1
LEIOPELMA HAMILTONI
L. hamiltoni subfossil remains were recorded from caves around Punakaiki; the
Heaphy River; Patarau; Takaka; and Mt Owen in the South Island. Also from the
Puketoi Range south of Dannevirke; Patoka in Hawkes Bay; and Waitomo in the
North Island (Fig. 1). However, the discovery of Archey-type frogs at Whareorino
Forest led Bell (1994) to suggest that these could be the Waitomo subfossil species
described by Worthy as L. hamiltoni. Bell (1994) further speculated that perhaps L.
hamiltoni was not in the northern North Island as Worthy (1987b) suggested, but
that northern subfossils represent Larcheyi, though these are a little larger in body
size than individuals from Coromandel populations (Thurley & Bell 1994).
2.2
LEIOPELMA HOCHSTETTERI
L. hochstetteri subfossil remains have been found in caves near Punakaiki; Karamea;
Paturau; and Takaka Hill in the South Island. Also from Hawkes Bay; and near
Waitomo in the North Island (Fig. 1).
2.3
LEIOPELMA WAITOMOENSIS (EXTINCT)
L. waitomoensis had a distribution wholly confined to the North Island. Its remains
were found in caves at Mangamuka near Kaitaia; Waipu; Waitomo; Hawkes Bay;
Puketoi Range; and Martinborough (Fig. 1).
3
2.4
LEIOPELMA MARKHAMI (EXTINCT)
L. markhami lived in both main islands, and its remains have been recovered from
Mangamuka in Northland to Te Anau in Fiordland (Fig. 1).
2.5
LEIOPELMA AURORAENSIS (EXTINCT)
L. auroraensis is so far known only from Aurora Cave on the western side of Lake Te
Anau in Fiordland (Fig. 1).
The disappearance of the presumed extinct species, and the commencement of the
decline in range of the surviving species, happened between 1000 and 2000 years
ago and are probably correlated with the arrival of kiore, Rattus exulans, in New
Zealand (Worthy 1987b).
FIGURE 1. FORMER DISTRIBUTION OF LEIOPELMA TAXA IDENTIFIED FROM
SUBFOSSILS (BELL 1994, AFTER WORTHY 1986, 1987B).
4
3.0 Present Distribution
3.1
HAMILTON'S FROG
Known only from a 600m2 rock bank (`frog bank') at 275m on Stephens
Island in Cook Strait. In May 1992, 12 frogs were transferred to the `frog
pit', a newly created habitat of approximately 72m2 within the nearest
remaining forest patch to the frog bank (Brown 1994).
3.2
MAUD ISLAND FROG
Present in a 15ha remnant of coastal forest on Maud Island, Pelorus Sound,
Marlborough Sounds. Another population has been established in a second forest
remnant above Boat Bay on the island following liberations made in 1984 and 1985
(Bell 1985, 1994). The species is expanding its range naturally on the island as
revegetation progresses. Some low-density populations now probably exist outside
the main forest remnant, generally below and to the north of it. For instance, early in
1994 a frog was found some 400m from the main forest (D. Brown, pers. comm.).
3.3
ARCHEY'S FROG
Found in three main areas of the Coromandel region of the North Island: Mount
Moehau; the central Coromandel Range from north of Tokatea to south of the TapuCoroglen saddle; and east of Paeroa in the southern Coromandel Ranges. Archeytype frogs (referred to subsequently in this plan as `L. archeyi') have been located in
Whareorino Forest, western King Country (Thurley & Bell 1994).
3.4
HOCHSTETTER'S FROG
Most widespread of Leiopelma species. Found in an extensive area in the eastern
Bay of Plenty and Raukumara Ranges to East Cape; and in scattered populations
elsewhere in the northern North Island, from Whareorino Forest, Pureora
Forest in the south, northwards to Otawa Forest (near Te Puke), and the
northern Kaimai Ranges, through the Coromandel, Hunua, Waitakere
and Warkworth ranges to Great Barrier Island and the Whangarei
district. Further unconfirmed reports are from near Lake Waikaremoana
and Pirongia Forest (the Pirongia record may have been of an introduced frog - P. de
Lange, pers. comm.).
Illustrations by Sonia Frimmel
5
3.5
CAPTIVE STOCKS
The following animals are currently held in captivity by Dr Ben Bell (Victoria
University of Wellington):
Maud Island frog: 13
Hamilton's frog:
1
Hochstetter's frog: 12
Archey's frog:
12
Although breeding has occurred over the last 10 - 15 years (in all but Hochstetter's),
only one froglet has reached adulthood (B.D. Bell pers. comm.).
FIGURE 2. KNOWN DISTRIBUTION OF EXTANT LEIOPELMA TAXA (BELL 1994).
6
4.0 Threats to Native Frogs
A complex of factors has affected New Zealand's frogs over recent geological time,
with different species varying in their vulnerability. Climatic factors, habitat
availability and interactions with introduced animals have all been implicated in
confining surviving species to the limited areas where they now occur and in
bringing about the extinction of species known only from subfossil records (Bell
1985). Principal continuing common threats are habitat destruction, impact of
introduced fauna, and possibly reduced genetic variation because of small
population size in at least some remnant populations. Particular threats faced by the
different frogs are:
4.1
HAMILTON'S FROG
Small population size: the Stephens Island frog bank probably supports only 150200 individuals (Newman 1990, Brown 1994) making this species one of the rarest
frogs in the world. Circumstantial evidence suggests that Hamilton's frog may not
be able to co-exist with certain introduced mammalian predators, such as rodents,
since Stephens Island is free of such predators. However, a feral cat population
became established in the island after 1894, but was exterminated early this century.
Studies of captive frogs indicate that Hamilton's frogs have lower fertility and
productivity compared to Maud Island frogs - possibly a consequence of small
population size following a genetic "bottleneck" (Daugherty et al. 1981).
4.2
MAUD ISLAND FROG
Although an estimate of their total numbers is 19,000 individuals (Bell & Bell 1994),
the species is restricted to just one island so is vulnerable to habitat destruction by
fire, or to the arrival of mammalian predators, which could be brought in with island
supplies, visiting boats, shipwrecks, or by swimming from the mainland (about 1km).
Over the last 10 years stoats have invaded the island at least twice (D. Brown, pers.
comm.).
4.3
ARCHEY'S FROG
Probably many thousands occur in total although precise information is lacking.
Very locally in the central Coromandel, densities as high as 8 frog/m2 have been
recorded (Bell 1994) cf. Hamilton's frog: up to 0.6 frogs/m2, and Maud Island frog: up
to 1.3 frogs/ml (Newman 1990). The main threat is continued depletion and
modification of habitats from exotic afforestation, farming, quarrying and mining
activities. The impact of introduced mammals on L. archeyi is not fully understood,
though goats, cattle and pigs have a detrimental impact at some Coromandel sites
(Bell 1985). At Whareorino predation has been recorded on "L. archeyi" by the
introduced golden bell frog Litoria aurea, and by mammals, possibly rodents
(Thurley & Bell 1994).
7
4.4
HOCHSTETTER'S FROG
Most widespread and numerous of Leiopelma species, although destruction or
modification of its habitat is still occurring, either directly through human activity
e.g. exotic afforestation, quarrying, roadworks, mining and stormwater discharge or
indirectly, e.g. impacts of feral goats (can cause accelerated erosion leading to the
silting up of frog streams - see Newman & Towns 1985). The extensive East Cape
populations are threatened with fragmentation due to goat impacts, especially on
the true left of the Motu River. Impacts occur through siltation and destabilisation
of watercourses, drying of moist scree habitats from loss of forest understorey and
failed regeneration after slips (C. Ward pers. comm.). The effect of introduced
mammalian predators is uncertain, but L. hochstetteri co-exists with them
throughout its range. However, research on the impacts of introduced predators,
including introduced frogs, on Hochstetter's frog, should be undertaken (see Section
9, topics 5 d & e).
Locally the species reaches densities as high as 4 - 5 frogs/m2 alongside suitable
watercourses, though availability of retreat sites markedly affects distribution (Bell
1985, D. Slaven, pers. comm.). For L. hochstetteri, numbers/100 m of watercourse
searched may be a better descriptor of relative density: up to 65 frogs/100 m of
stream (minimum number alive) have been observed, but such densities are very
localised (D. Slaven, pers. comm.). Daugherty et al. (1981) found less genetic
variability in Hochstetter's frog than in the other species and suggested the
concentration of L. bocbstetteri along watercourses may result in the size of
individual populations of this species being smaller than those of the native frogs
which occupy less linear habitats. Further, the localisation of these small
populations may make L. h ochstetteri more susceptible to environmental
fluctuations such as floods or siltation following rains or ground disturbance.
4.5
GLOBAL DECLINES OF AMPHIBIAN POPULATIONS
Worldwide, the populations of many amphibian species, in widely scattered habitats,
appear to be in severe decline (e.g., Pechmann et al. 1991, Tyler 1991); other
amphibians show no such declines. There is no known single cause for the declines,
but their widespread distribution suggests involvement of global agents, for instance
some atmospheric source. Industrial chemicals, increased UV-B radiation, and
infectious disease, especially viral diseases, are all being investigated as possible
causes.
In response to international concern, in 1992 the IUCN Species Survival
Commission (SSC) established a Declining Amphibian Populations Task Force
(DAPTF). DAPTF's mission is to determine the nature, extent and causes of declines
of amphibians throughout the world, and promote means by which the declines can
be halted or reversed. DAPTF produces a quarterly newsletter, "Froglog" which
reports latest knowledge on the extent of declines, and research findings on possible
causes. Of particular concern is the speed of many declines, some occurring over
periods of as little as three months. No evidence exists that the status of NZ frogs
has changed significantly over the past 10 years, but given the paucity of long-term
monitoring, there is no room for complacency.
8
5.0 Ability to Recover
Clearly, the status of Hamilton's and Maud Island frogs gives rise to greater concern
than that for Archey's and Hochstetter's frogs. Unlike the latter two, Hamilton's and
Maud Island frogs are known to occur on just one island each. Both islands are,
however, predator-free and the Maud Is frog at least, has demonstrated an ability to
respond to habitat improvement (revegetation).
There are a number of other predator-free islands which have potential as transfer
sites for both species. Establishment of further populations on new islands will
significantly improve the conservation prospects for these two species. In fact a
new population of Maud Island frogs has already been established - in a forest
remnant on Maud Island, separate from its main habitat (Bell 1994), and 12
Hamiltons frogs have been transferred to a purpose built "frog pit" on Stephens
Island (Brown 1994).
It may simply be a coincidence that Maud Island and Hamilton's frogs are restricted
to islands free of introduced predators. This could be tested by trying to establish
populations of Maud Island frog on islands where some introduced predators occur,
or at mainland sites. Success at such sites would greatly increase the conservation
prospects for these species.
The status of Archey's and Hochstetter's frogs should remain stable if not improve, as
long as there is a halt to habitat destruction. They both have an apparent ability to
survive in association with introduced frogs and mammals, despite a certain degree
of predation. A more accurate indication of the level of predation, as well as long
term monitoring of native frog populations, will be necessary however before it can
be determined whether or not this level is sustainable. Both demography and
habitat factors need to be monitored. The results of such work will improve our
ability to select transfer sites, determine numbers for release and areas for further
survey. The possibility of finding new populations, in light of the recent discovery at
Whareorino, gives some cause for optimism.
Terrestrial species of Leiopelma have laid eggs in captivity, although captive-held L.
hochstetteri have done so only occasionally, probably due to difficulties in recreating
suitable breeding sites for this species in terraria (Bell 1985, Sharbel and Green
1992). Only one native frog has been raised to adulthood. Self-sustaining captive
populations would ultimately assist recovery by providing an alternative source of
frogs for research and advocacy purposes.
9
6.0 Options for Recovery
All options for recovery assume some level of monitoring. Monitoring approaches,
along with suggestions for further survey and taxonomic revision, are included in
sections 7.0 and 8.0.
6.1
HAMILTON'S FROG
Option 1
Do nothing more. That is, maintain rodent/stoat free status of Stephens Island and
maintain current revegetation, fencing and weed control programmes, as required by
the draft island management agreement (I. Millar pers. comm.) as well as the tuatara
recovery plan (Cree & Butler 1993). The population size may remain stable or even
expand as a consequence however, since Stephens Island is the sole known location
for the species, extinction, owing to unpredictable events such as rat invasion, is
always a possibility.
Option 2
Maintain current island management. Select and prepare a site on another island
free of introduced mammalian predators for the establishment of a new population
and attempt a transfer of frogs.
Option 3
As for option 2 but, in addition, establish one long-term self sustaining captive
population.
Preferred option
The option chosen for the duration of this recovery plan is Option 1. Within the
next 5 - 10 years, however, Option 2 must be considered. The population of the frog
bank and the frog pit combined is as yet too small to sustain the removal of more
than 15 individuals within the five year period covered by this plan. It would be
prudent, though, to select, as soon as possible, a site on another island, free of
introduced mammalian predators, for the establishment of a new population.
6.2
MAUD ISLAND FROG
Option 1
Do nothing more. The population size may remain stable or even expand as a result
of current island management (maintenance of current rodent/stoat-free status and
11
"controlled" natural regeneration). Maud Island remains the sole known location for
the species and extinction is always a possibility, owing to unpredictable events
such as rat or stoat invasion.
Option 2
Maintain current island management. Investigate potential transfer sites and
establish a new population on at least one further predator-free island; establish one
long-term self sustaining captive population.
Option 3
As for option 2 but consider establishment of new populations of Maud Island frogs
on islands where some introduced predators occur, or at mainland sites.
Preferred option
The option chosen for the duration of this recovery plan (1-5 years) is Option 2.
Within the next 5-10 years, however, Option 3 should be considered.
6.3
ARCHEY'S FROG
Option 1
Do nothing more. Current management (e.g., control of introduced mammals) will
be maintained. The total frog population might remain much the same as at present,
but it could also decline as a result of habitat degradation and/or loss through
unpredictable events either on or off Conservation land.
Option 2
Advocate for protection of all habitat containing populations ofArchey's frog.
Option 3
As for option 2 but, in addition, establish one long-term self sustaining captive
population for supply of frogs for research and advocacy purposes.
Preferred option
The option chosen for the duration of this recovery plan is Option 2. Captive
breeding is currently a low priority for this species, although if long-term monitoring
indicates a significant decline then establishment of a captive population should be
considered, as an alternative supply of frogs.
12
6.4
HOCHSTETTER'S FROG
Option 1
Do nothing more. Current management in some areas will include control of
introduced mammals. The total frog population might remain much the same as at
present, but it is more likely to decline as a result of habitat degradation and/or loss
through unpredictable events, either on or off Conservation land. Where no
conservation management is taking place, the likelihood of decline is even greater.
Option 2
Advocate for the protection of Hochstetter's frog habitat to avoid fragmentation or
destruction of existing populations, particularly in Northland
Option 3
As for Option 2, but in addition transfer frogs from degraded Northland sites, e.g.,
Brynderwyn Range, to protected areas north of Waipu Caves which are to be
identified in the Draft Northland Conservation Management Strategy (1995) as being
priority areas for the management of threatened species.
Option 4
As for Option 3 but, in addition, establish one long-term self-sustaining captive
population for supply of frogs for research and advocacy purposes.
Preferred option
The option chosen for the duration of this recovery plan is Option 2, however
assessments of degraded Northland sites should be made and, if practicable,
recommendations made for their restoration. Conservation measures proposed for
other species co-existing with Hochstetter's frog, such as Chevron skink at Te
Paparahi, Great Barrier Island, will also benefit this species (Towns & McFadden
1993). The need for a captive population is considered a low priority in the shortterm.
13
7.0 Recovery Strategy:
Goal and Objectives
LONG TERM GOAL
The long-term (50-year) goal of this recovery programme is to maintain and
enhance, in the wild, existing genetic stocks of native frogs (Leiopelma spp.).
SUMMARY OF OBJECTIVES FOR THE DURATION OF THIS
PLAN
1. Maintain as far as is practicable, all known populations of native frog and protect
them from adverse human impacts.
2. Work towards establishing two new wild populations of Hamilton's frog (one on
Stephens Island and a second on another predator-free island).
(associated research requirement: translocation methods/strategies).
3. Establish a population of the Maud Island frog on a second predator-free island.
(associated researcb requirement , taxonomic status, translocation methods/
strategies, monitoring techniques).
4. Establish long-term monitoring at selected sites for all species of native frog to
determine population trends.
(associated research requirements: development of standardised monitoring
methods; effects of 1080; impact from introduced mammals/frogs/birds).
5. Survey areas of potential habitat seeking to locate further as yet unknown,
populations of native frogs and integrate all existing native frog distribution data.
(associated research requirement. , genetic population studies)
6. Raise public awareness and public advocacy for protection of native frogs and
their habitat.
7. Maintain at least one long-term, self-sustaining captive population of each species
of native frog. (Low Priority)
15
8.0 Recovery Strategy: Work Plan
Actions required are listed in priority order.
OBJECTIVE 1
Maintain, as far as is practicable, all known populations of native frog, and
protect them from adverse human impacts.
Explanation
Except in Northland, the majority of frog populations occur in protected areas.
Where habitat is not legally protected, formal protection of this land should be
sought (e.g., establishment of scenic reserves, wildlife management reserves, etc.).
Whether habitat has legal protection or not, existing human activities, especially
forestry, farming practices on adjoining land and quarrying operations will continue
to place certain mainland populations at risk. These activities and increasing animal
pest impacts may lead to further loss of native vegetation cover, accelerated erosion
and the silting-up of streams destroying frog habitat. DoC staff need to be aware of
the location of frogs in their Conservancy, activities (both on and off Conservation
land) which may impact upon frog habitat, and make efforts to mitigate these factors
where possible. Control of introduced mammals, especially goats and pigs, in areas
of frog habitat is of particular importance.
Action
Advocate, through local government, for the protection of all native frog
populations from adverse human impacts (earthworks or catchment vegetation
disturbance) .
Ensure that surveys of potential frog habitat are undertaken prior to any
development proceeding (either on site or upstream) and that, where frogs are
found, disturbance is minimised or prohibited.
Where habitat containing native frog populations is not legally protected, formal
protection of the land should be sought (e.g., acquisition covenant) where
adequate protection cannot be achieved elsewhere (e.g., Resource Management
Act controls).
Key Personnel
DoC Northland,Auckland, Waikato, Bay of Plenty, East Coast, Nelson/Marlborough.
17
OBJECTIVE 2
Work towards establishing two new wild populations of Hamilton's frog.
Explanation
The security of this species should be increased by extending its range on Stephens
Island by creating new habitat, and by having it represented on at least one further
island. The second island should be within the Cook Strait-Marlborough Sounds
region and be free of introduced mammalian predators. Should these transfers be
successful, islands outside of this area could be considered for further transfers. In
addition, the extensive boulder banks at the western end of Stephens Island should
be thoroughly searched for frogs. If no frogs are found, these sites could be
developed (revegetation, etc.) as new habitats for the species.
Progress
During 1991, a new habitat, the `frog pit', was created on Stephens Island 40m from
the frog bank. In May 1992 12 adult frogs were transferred to the frog pit and seven
have since been recaptured there (Brown 1994).
Nukuwaiata (Inner Chetwode) Island, 25 km from Stephens Island, is being
investigated for consideration as the second island for Hamilton's frog. It is heavily
forested and climatically and floristically very similar to Stephens Island (Brown
1994). An attempt to rid Nukuwaiata of kiore seems to have been successful and
habitat suitable for the frogs appears to be present. If necessary, it can be enhanced
or new habitat created.
Action
Transfer further frogs to the frog pit once breeding at this site has been
confirmed.
Link the frog pit and frog bank by a corridor of rock-filled pits and trenches.
Plant forest species on either side of the corridor (eventually, it is hoped that the
frog pit and frog bank populations will merge).
Investigate and decide, in consultation with Recovery Group, Kaupapa Atawhai
Manager and local iwi, the suitability of Nukuwaiata Island for frog transfers. If
necessary, enhance potential frog habitat on Nukuwaiata Island, or create new
habitat.
Key Personnel
DoC Nelson/Marlborough.
18
OBJECTIVE 3
Establish a population of the Maud Island frog on a second predator-free island.
Explanation
The security of this species should be increased within the next five years by having
it represented on at least one further predator-free island. It may simply be a coincidence that Maud Island and Hamilton's frogs are restricted to islands free of
introduced predators, not withstanding the occasional invasion of Maud Island by
stoats. To test this, an attempt should be made, within the next 5-10 years, to
establish a population of Maud Island frogs on an island where some introduced
predators occur (e.g., island in Tennyson Inlet), or at a mainland site (Tennyson Inlet
mainland, or Mt Shewell Scenic Reserve).
Action
Identify a predator-free island suitable for establishing a new population of the
Maud Island frog. Ensure that the Maud Island frog is not transferred to an island
identified as a transfer site for Hamilton's frog.
Transfer Maud Island frogs to the new site and monitor success
Investigate and decide, in consultation with Recovery Group, Kaupapa Atawhai
Manager and local iwi, on the suitability of islands where some introduced
predators occur, or mainland sites, for further frog transfers.
Key Personnel
DoC Nelson/Marlborough to select transfer site in consultation with Recovery
Group.
OBJECTIVE 4
Establish long-term monitoring sites for all species of native frog to determine
population trends.
Explanation
Although no evidence exists that the status of NZ frogs has changed to any
significant extent over the last 10 years (some local populations of Hochstetter's
frog may have been lost), monitoring sites should be established to ensure that there
is no cause for concern (see section 4.5). The semiaquatic Hochstetter's frog is very
sensitive to catchment modification (e.g., McLennan 1985, Newman &Towns 1985)
so is likely to prove a valuable biological indicator of catchment stability and, by
extension, of the effectiveness of catchment management. Generally, frogs are held
to be excellent biological indicators of the health of the environment because of
such attributes as their permeable skins and, in many species, their life cycles which
include both aquatic and terrestrial phases (Heyer et al 1994).
19
Progress
Populations of Hamilton's and Maud Island frogs are already being monitored (Bell &
Bell 1994, Brown 1994), as is the central Coromandel (Tapu Ridge) population of
Archey's frog (Bell 1994). At sites 13 and 14 (below), land tenure belongs to
Auckland Regional Council, staff of whom have expressed interest in frog surveying
(S. Boyd, pers. comm.). Some work has already been done at Hunua in relation to a
1080 operation (McNaughton & Greene 1994).
While Archey's and Hochstetter's frog rank as species at less risk than L. hamiltoni
or L. Maud Island, both, especially L. hochstetteri, occur in isolated populations of
variable size and extent. Some of these isolates may be threatened or vulnerable. In
genetically and geographically discontinuous species, every population may be an
important component in biogeographic diversity since each isolate may represent
"an emergent historical entity" (Green 1994).
Geographic subdivisions in
Hochstetter's frog can be identified from variation in supernumerary chromosome
number and, particularly, the morphology of the sex chromosome, in conjunction
with isozyme evidence (Green 1994). Such findings suggest that at least some
conservation measures for frogs might be best framed population by population
rather than at the species level. Monitoring is best done at the population level. A
listing of populations in priority order for monitoring would be:
1. Stephens Island:
Hamilton's frog: frog bank and frog pit.
2. Maud Island:
Maud Is frog: main forest remnant and Boat Bay.
Archey-type and Hochstetter's frogs.
3. Whareorino:
Hochstetter's frog (cytogenetically distinct from North
4. Great Barrier Is:
Island populations).
Hochstetter's frog populations of Northland appear to be
5. Waipu:
the most threatened of North Island populations.
Hochstetter's frogs from Mt Ranginui are the most
6. Rangitoto Range:
chromosomally and biochemically distinctive of the
North Island populations.
7. South Coromandel: Archey's and Hochstetter's frogs - particular threats from
mining in this area.
8. Otawa Forest:
Hochstetter's frog - threats from quarrying in this area.
9. East Cape:
Hochstetter's frog (Motu River catchment, includes Toatoa
and Whanarua; Pukeamaru Range; Waioeka).
10. Warkworth:
Hochstetter's frog.
11. Central Coromandel: Archey's and Hochstetter's frogs (the former are already
being monitored at Tapu Ridge).
12. North Coromandel: Archey's and Hochstetter's frogs (Moehau Range).
13. Hunua Mountains:
Hochstetter's frog.
Hochstetter's frog.
14. Waitakere:
Action
Conservancy representatives of the recovery group are to recommend final sites
for monitoring. When doing so, priority should be given to populations put at
risk from 1080 programmes or other resource consents, as well as to populations
within areas assigned to be managed as "mainland islands".
20
Not all populations need to be monitored at the same intensity, greatest effort
should be devoted to those of highest priority. Low priority populations may
only require checking at 3-5 year intervals. Monitoring techniques could range
from rigorous assessments of population density (involving the permanent
marking of individuals, e.g., Stephens Island frog pit, Maud Island Boat Bay) to
simple indexing (timed searches along permanent transects - measuring snoutvent length (SVL) being a handy adjunct to abundance). Techniques most
appropriate to specific circumstances should be decided upon by the recovery
group in consultation with the DoC Conservancies concerned. As part of the
monitoring, habitat features must also be assessed. There is an urgent need to
standardise monitoring procedures for each species. For a summary of interim
monitoring procedures refer to Appendix 2.
Key Personnel
Hamilton's frog:
DoC Nelson/Marlborough;
Maud Island frog:
Dr B. D. Bell (VUW) in association with DoC Nelson/Marlborough;
Archey's frog:
DoC Waikato, Dr B. D. Bell (VUW);
Hochstetter's frog: DoC Northland, Auckland, Waikato, Bay of Plenty, East Coast;
Auckland Regional Council
OBJECTIVE 5
Survey potential habitat to locate further poulations of native frog and integrate
all existing native frog distribution data.
Explanation
Native frogs are small, nocturnal and cryptically coloured; they are easily overlooked. Many populations may exist which we are unaware of - it was not until
1991 that Archey-type and Hochstetter's frogs were found at Whareorino. There is a
need to firstly identify priority areas for survey and secondly to ensure that all
existing information on frog distribution is readily available.
Priority areas for searching (ordered by species) are:
Hamilton's frog
1. Stephens Island
Hamilton's & Maud Island frogs
1. D'Urville Island
2. Chetwode Islands
3. Marlborough Sounds mainland
4. Arapawa Island
5. North West Nelson (especially Paturau coast)
21
Archey's & Hochstetter's frogs
1. Western King Country
2. Pirongia
Hochstetter's frog
1. South of East Cape
2. Southern Urewera
3. Kaimai-Mamaku
4. Central and northern Northland
Distribution data on native frogs must be made more easily available to DoC officers
and bona fide research workers. Dr B. D. Bell (VUW) has extensive distribution
records of native frogs and further records are held as part of DoC's Amphibian and
Reptile Distribution Scheme. These records must be combined, ideally as part of
DoC's Amphibian and Reptile Distribution Scheme.
Action
Conservancies will determine survey sites and conduct surveys annually in
consultation with the Recovery Group.
DoC Science & Research and Dr B. D. Bell (VUW) to advise if data are in a form
that can be readily exchanged between DoC and VUW Due recognition should
be given to Dr Ben Bell for gathering and providing records.
Key Personnel
DoC Nelson/Marlborough, East Coast, Bay of Plenty, Waikato, Northland.
DoC Science & Research, Dr B. D. Bell (Victoria University).
OBJECTIVE 6
To raise public awareness of native frogs to advocate protection of their habitat.
Explanation
Native frogs are cryptic creatures which are easily overlooked. Scientifically,
however, quite a lot is known about them. There is a need to inform the public, local
bodies, regional councils and private landowners about native frogs, and to
encourage their concern for, and involvement in, the protection of native frog
habitat.
Progress
A "fact sheet" about native frogs has been produced (by DoC), giving descriptions of
both native and introduced frogs and their likely habitats (see Appendix 3).
22
Action
Distribute the fact sheet to organisations involved with land management, and
those involved in outdoor pursuits (tramping, hunting, etc.). Copies of the fact
sheet could be left in appropriate back-country huts.
Prepare a popular article on native frogs and their conservation for contribution
to publications such as Forest & Bird magazine, Straight Furrow etc.
Produce a video on frog conservation to be used at captive institutions in lieu of
a live captive display. Existing material should be checked first.
Seek the support of non-government organizations to assist with frog advocacy.
Key Personnel
DoC Science & Research, Threatened Species Unit, & Public Awareness Unit in
consultation with Recovery Group.
OBJECTIVE 7
Maintain at least one long-term, self-sustaining population of each species of
native frog (low priority).
Explanation
Terrestrial species of Leiopelma have been bred in captivity, but captive-held
colonies of L. hochstetteri breed only occasionally. Further, for all species, survival of
captive-bred young to adulthood has been poor. Improved captive husbandry
techniques leading to the establishment of self-sustaining colonies would allow
supply of frogs for research (e.g., toxic bait trials, predator response trials),
advocacy/education and even, perhaps, establishment of new wild populations.
Ultimately, the aim should be to maintain at least one long-term, self-sustaining
captive population of each species of native frog. Such an aim is unlikely to be
achieved within the next five years (duration of this plan), especially for Hamilton's
frog. Priority for L. hamiltoni must be the establishment of at least two new wild
populations (Objective 2) and only when this has happened will some individuals
be available to be taken into captivity.
Action
Refine techniques for maintaining and breeding Hochstetter's frog in captivity.
For Hochstetter's, Archey's and Maud Island frogs - improve survival of captive
bred young to adulthood.
Key Personnel
Dr Ben D. Bell (Victoria University) in consultation with Recovery Group and DoC
Species Protection Division.
NOTES TO SECTION S
a discrete area on the mainland intensively managed as an entire ecosystem i.e., as
if it were an offshore island.
23
9.0 Research Priorities
Topics are listed in order of priority.
a) Review and test techniques for monitoring frog populations in order to
recommend most suitable protocols for NZ species.
Explanation
Develop standard techniques for monitoring; also tagging/monitoring techniques
for individual frogs. When developing techniques, reference should be made to
Heyer et al (1994) "Measuring and Monitoring Biological Diversity: Standard
Methods for Amphibians".
b) Effect on frog populations, of aerially broadcast poisons used to control possums.
Explanation
Determine proportion of individuals in frog populations which would be at risk
of consuming poison baits, or of secondary poisoning during a control operation.
Conduct non-toxic marker trials. Observe impact of toxic baits on captive
individuals. Document impact on local populations of Archey's and Hochstetter's
frogs before, during and after control operations. A research contract has been
negotiated between DoC Science & Research and Dr B.D. Bell (VUW) to
investigate the effects of 1080 on native frog populations. Some basic work has
already been done by Auckland Regional Council in the Hunua Ranges
(McNaughton & Greene 1994).
c) Refinement of frog translocation methodologies.
Explanation
Research should aim at providing protocols for evaluating potential habitats, safe
transportation of frogs, and schemes for monitoring the survivorship of
translocated populations (latter may involve revaluation of marking and/or
tagging procedures).
d) Impact of introduced mammalian and avian predators on surviving mainland
populations.
Explanation
What mammals and/or introduced birds are predators of native frogs, and which
of these are of greatest threat to the frogs? Leiopelma are known to possess a
suite of anti-predator mechanisms (Bell 1985b, Green 1988b). Any study should
assess the significance of frog paratoid secretions as a deterrent to predators.
e) Impact of introduced frogs on surviving mainland populations.
Explanation
Document the extent and the consequence of predation and competition from
introduced frogs. At Whareorino, predation was recorded on "L. archeyi" by the
golden bell frog Litoria aurea (Thurley & Bell 1994). Although native frogs were
once distributed along the west coast of the South Island (Worthy 1987b), this
area is now extensively occupied by the whistling frog Litoria ewingi - was
competitive exclusion involved?
25
f) Genetic population studies.
Explanation
Establish the taxonomic status of the Maud Island frog, and the Archey-type frog
at Whareorino. Refine understanding of what constitutes a discrete population
(has implications for possible translocations). Note that research being
conducted by Bruce Waldman (University of Canterbury) is basically concerned
with developing non-destructive tools to characterise genetic variation within
frogs.
9) Demography, behaviour and habitat requirements of Archey's and Hochstetter's
frogs.
Explanation
Further information is required on habitat requirements (limits of tolerance),
recruitment of juveniles into populations, and behaviour in relation to daily
activity patterns (emergence). This information will be of importance in any
assessment of potentially adverse impacts on native frogs (see topics b, d and e,
page 19).
26
References
Bell, B.D. 1982: The amphibian fauna of New Zealand. In: Newman, D.G. ed. New Zealand
herpetology. Wellington, New Zealand Wildlife Service occasional publication no. 2. Pp. 2789.
Bell, B.D. 1985a: Conservation status of the endemic New Zealand frogs. In: Grigg, G.; Shine, R.;
Ehmann, H. eds. Biology of Australasian frogs and reptiles. Chipping Norton, Surrey Beatty.
Pp. 449-458.
Bell, B.D. 1985b: Development and parental care in the endemic New Zealand frogs. In: Grigg, G.;
Shine, R.; Ehmann, H. eds. Biology of Australasian frogs and reptiles. Chipping Norton,
Surrey Beatty. Pp. 269-278.
Bell, B.D. 1994: A review of the status of New Zealand Leiopelma species (Anura: Leiopelmatidae),
including a summary of demographic studies in Coromandel and on Maud Island. New
Zealand journal of zoology 21:341-349.
Bell, B.D.; Newman, D.G.; Daugherty C.H. 1985: The ecological biogeography of the archaic New
Zealand herpetofauna (Leiopelmatidae, Sphenodontidae). In: Grigg, G.; Shine, R.; Ehmann, H.
eds. Biology of Australasian frogs and reptiles. Chipping Norton, Surrey Beatty. Pp. 99-106.
Bell, E.A.; Bell, B.D. 1994: Local distribution, habitat, and numbers of the endemic terrestrial frog
Leiopelma hamiltoni on Maud Island, New Zealand. New Zealand journal of zoology 21:
437-442.
Brown, D. 1994: Transfer of Hamilton's frog, Leiopelma hamiltoni, to a newly created habitat on
Stephens Island, New Zealand. New Zealand journal of zoology 21: 425-430.
Cree,A. 1985: Water balance of New Zealand's native frogs. In: Grigg, G.; Shine, R.; Ehmann, H. eds.
Biology of Australasian frogs and reptiles. Chipping Norton, Surrey Beatty Pp. 361-371.
Cree,A. 1988: Effects of arginine vasotocin on water balance of three leiopelmatid frogs. General
and comparative endocrinology 72:340-350.
Cree,A.; Butler, D. 1993: Tuatara Recovery Plan. Threatened Species Recovery Plan Series No. 9.
Threatened Species Unit, Department of Conservation.
Daugherty, C.H.; Bell, B.D.; Adams, M.; Maxson, L.R. 1981: An electrophoretic study of genetic
variation in the New Zealand frog genus Leiopelma. New Zealand journal of zoology 8:
543-550.
Daugherty C.H.; Maxson, L.R.; Bell, B.D. 1982: Phylogenetic relationships within the New Zealand
frog genus Leiopelma: immunological evidence. New Zealand journal of zoology 9:239242.
Department of Conservation 1995: Draft Conservation Management Strategy for Taitokerau,
Northland. 2 volumes.
Duellman, W E. 1975: On the classification of frogs. Occasional papers of the Museum of Natural
History, University of Kansus 42:1-14.
Green, D.M. 1988a: Cytogenetics of the endemic New Zealand frog, Leiopelma hochstetteri:
extraordinary supernumerary chromosome variation and a unique sex chromosome system.
Chromosoma 97:55-70.
Green, D.M. 1988b: Antipredator behaviour and skin glands in the New Zealand native frogs, genus
Leiopelma. New Zealand journal of zoology 15:39-45.
Green, D.M. 1994: Genetic and cytogenetic diversity in Hochstetter's frog, Leiopelma hochstetteri,
and its importance for conservation management. New Zealand journal of zoology 21:
417-424.
Green, D.M.; Cannatella, D.C. 1993: Phylogenetic significance of the amphicoelous frogs,
Ascaphidae and Leiopelmatidae. Ecology ethology evolution 5: 233-245.
27
Green, D.M.; Sharbel,TE; Hitchmough, R.A.; Daugherty, C.H. 1989: Genetic variation in the genus
Leiopelma and relationships to other primitive frogs. Zettschrift fur Zoologische
Systematik and Evoluntionsfurschung 27:65-79.
Green, D.M.; Zeyl, C.; Sharbel,TE 1993: The evolution of hypervariable sex and supernumerary
chromosomes in the relict New Zealand frog, Leiopelma hochstetteri. Journal of
evolutionary biology 6:417-441.
Heyer, WR.; Donnelly, M.A.; McDiarmid, R.W; Hayek, L.C.; Foster, M.S. 1994: Measuring and
monitoring biological diversity: standard methods for amphibians. Washington, D.C.,
Smithsonian Institution Press. 364p.
McLennanjA. 1985: Some observations on Hochstetter's frog in the catchment of the Motu River,
East Cape. New Zealand.journal of Ecology 8:1-4.
McNaughton,A.; Greene, B. 1994: The effect of 1080 on the native Hochstetter's frog (Leiopelma
hochstettert) population in the Hunua Ranges. Unpublished report prepared for the
Auckland Regional Parks Service.
Molloyj; Davis,A. 1994: Setting priorities for the conservation of New Zealand's threatened plants
and animals. (Second edition collated by C. Tisdall). Wellington, Department of
Conservation.
Newman, D.G. 1990: Activity, dispersion, and population densities of Hamilton's frog (Leiopelma
hamiltont) on Maud and Stephens Islands, New Zealand. Herpetologica 46:319-330.
Newman, D.G.; Towns, D.R. 1985: A survey of the herpetofauna of the northern and southern
blocks, Great Barrier Island, New Zealand. Journal of the Royal Society of New Zealand
15:279-287.
Pechmann, J.H.K.; Scott, D.E.; Semlitsch, R.D.; Caldwell, J.P; Vitt, L.J.; Gibbons, J.W 1991: Declining
amphibian populations: the problem of separating human impacts from natural fluctuations.
Science 253: 892 -895.
Sharbel,TE; Green, D.M. 1992: Captive maintenance of the primitive New Zealand frog, Leiopelma
hochstetteri. Herpetological review 23:77-79.
Towns, D.; McFadden, I. 1993: Chevron Skink Recovery Plan. Threatened Species Recovery Plan
Series No. 5. Department of Conservation.
Thurley,T; Bell, B.D. 1994: Habitat distribution and predation of a western population of terrestrial
Leiopelma (Anura: Leiopelmatidae) in the northern King Country, New Zealand. New
Zealand journal of zoology 21:431-436.
Tyler, M.J. 1991: Where have all the frogs gone? Australian natural history 23:618-620.
Worthy,TH. 1987a: Osteology of Leiopelma (Amphibia: Leiopelmatidae) and descriptions of three
new subfossil Leiopelma species. Journal of the Royal Society of New Zealand 17:201251.
Worthy, TH. 1987b: Palaeoecological information concerning members of the frog genus
Leiopelma: Leiopelmatidae in New Zealand. Journal of the Royal Society of New Zealand
17: 409-420.
28
Acknowledgements
The compilation of this plan was undertaken intermittently over a period of three
years (1993-1995) largely because of the intervention of higher priority work. While
this period may seem excessive, it has allowed for extensive consultaiton and it is
with gratitude that I acknowledge the many people who generously provided advice
and comment on various drafts, in particular Peter Anderson, Ben Bell, Shaarina Boyd,
Derek Brown, Alison Cree, David Green, David King, Ian Millar, Keith Owen, Richard
Parrish, David Slaven, Rick Thorpe, David Towns, Dick Veitch, Bruce Waldman, Chris
Ward, Tony Whitaker and Thelma Wilson. My very special thanks, though, go to
Suzanne Clegg who, as DoC's Threatened Species Unit contact for native frogs, gave
me much appreciated support and encouragement to see this project through to its
completion.
29
Appendix l:
Estimate of Funding Required
An estimate of funds required to carry out projects outlined in this recovery plan for
the next five years are given below. Estimates exclude salaries of DoC staff, but
include provision for contracts where these may be involved (e.g., for research
projects). The table outlines ongoing costs over 5 years. One-off projects and
research objectives are outlined below.
5 YEARS
5 YEARS
5 YEARS
5 YEARS
Monitoring
Establish
new popns
Attend
recovery
group
Survey
Total funds
required over
five years
Funds
required
per year
Northland
$ 7,500
-
$ 2,500
$ 3,000
$10,500
$ 1,500
Auckland
$ 7,500
-
$ 2,000
-
$7,000
$ 1,400
Waikato
$12,500
-
$ 2,000
$ 5,000
$17,000
$ 3,400
Bay of Plenty
$ 5,000
-
$ 2,000
-
$8,000
$ 1,000
East Coast
$7,500
-
$ 2,000
$ 3,000
$12,000
$ 2,400
Nelson/Marl.
$ 7,500
$15,000'
$ 2,500
$ 5,000
$27,500
$ 5,400
-
-
$ 2,000
-
$ 2,000
$
$47,500
$15,000
$15,000
$16,000
$84,000
$15,500
Science &
Research
TOTAL
400
* Continued development of the frog pit, monitoring survival of transferred frogs to the pit,
linking the pit to the frog bank, assessing suitability of Nukuwaiata Is. for Hamilton's frog.
One-off tasks
Nelson/Marlborough Conservancy:
• Select and transfer Maud Island frogs to a new site:
$ 5,000
Research objectives
•
•
•
•
Effects of 1080 on frog populations
Review and testing of monitoring techniques
Refinement of translocation techniques
Impact of predators (introduced mammals/birds/frogs)
on native frog populations
• Refinement of captive breeding techniques
Total research funds required over five years
TOTAL FUNDS REQUIRED OVER FIVE YEARS
$ 10,000
$ 9,500
$10,000
$15,000
5,000
$49,500
$ 138.500
Appendix 2:
Monitoring Techniques for
Native Frogs
This recovery plan identifies that there is an urgent need for the standardisation of
monitoring procedures for each species of native frog. Techniques that have been
used in New Zealand were reviewed by the recovery group during the course of the
development of this plan. As a result of these discussions, interim monitoring
procedures forArchey's and Hochstetter's frogs were agreed upon and are presented
below. There is however a need for research aimed at reviewing and testing
monitoring techniques for New Zealand species, in order to recommend those most
suitable. Determining the most suitable monitoring protocols is noted as being the
highest priority for research in the plan.
It is recognised in the plan that not all populations need to be monitored at the
same intensity. Greatest efforts should be devoted to those of highest priority.
Lower priority populations may only require checking at 3-5 year intervals. Some
populations are already being closely monitored, e.g., Stephens and Maud Island
populations, and central Coromandel populations (Tapu ridge), the latter involving
the marking of individuals within permanent quadrats.
Monitoring techniques could range from rigorous assessments of population density
(involving the permanent marking of individuals) to simple indexing (timed
searches along permanent transects). Techniques most appropriate to specific
circumstances should be decided upon by the recovery group in consultation with
the DoC Conservancies concerned.
Typically, on any sampling occasion, at least the following should be recorded:
time spent observing (start/finish times)
weather conditons 24 hours prior to search
rain during search
air temperature and relative humidity at the start and finish of search
physical description of habitat and of where each frog was found: on ground
(substrate: rock, soil, leaf litter, logs), under cover (rock, logs, etc), in foliage, on
tree trunk, height from ground.
sketch map of area searched, with approximate location of frogs
snout-vent length of frogs, weight (useful but not essential)
PROPOSED MONITORING TECHNIQUE FOR ARCHEY'S
FROG
monitor at least 2 to 5 transects (100m x 2m) side by side
monitor in late January-February
monitor during the day
lift rocks/logs, search in vegetation up to head height
record a physical description of habitat, including photopoints
record climatic information
PROPOSED MONITORING TECHNIQUE FOR
HOCHSTETTER'S FROG
monitor 2 x 100m transects, upstream verge (i.e., splash zone)
monitor in late January-February
monitor during the day
search in all suitable habitat along the transect (under rocks, vegetation, in
crevices), all non-destructive
record a physical description of habitat, including photopoints.
record climatic information
Appendix 3:
Advocacy Pamphlet
Appendix 4:
Published Recovery Plans
Stitchbird
($15)
Approved 1996
Brown teal
($15)
Approved 1996
Native frogs
($15)
Approved 1996
Dactylanthus taylorii
($15)
Approved 1995
Bat (Peka peka)
($15)
Approved 1995
Otago and grand skinks
($15)
Approved 1995
Giant land snail
($15)
Approved 1995
South Island saddleback
($15)
Approved 1994
Takahe
($15)
Approved 1994
New Zealand Dotterel
($15)
Approved 1993
Tuatara
($15)
Approved 1993
Mohua (yellowhead)
($15)
Approved 1993
Subantarctic teal
($15)
Approved 1993
Kowhai ngutukaka
($15)
Approved 1993
Chevron skink
($15)
Approved 1993
Black stilt
($15)
Approved 1993
Whitaker's and robust skinks
($15)
Approved 1992
North Island kokako
($15)
Approved 1991
Kiwi
($15)
Approved 1991
-
Approved 1991
($10)
Approved 1991
Out of print
Approved 1989
Yellow-eyed penguin*
Blue duck **
Kakapo
Copies may be ordered from:
DOC: Science Publications
Science & Research Division
R O. Box 10420
WELLINGTON, N.Z.